polysaccharide glycogen A polydisperse, highly branched glucan composed of chains of D-glucopyranose residues in alpha(1->4) glycosidic linkage, joined together by alpha(1->6) glycosidic linkages. A small number of alpha(1->3) glycosidic linkages and some cumulative alpha(1->6) links also may occur. The branches in glycogen typically contain 8 to 12 glucose residues. CAS:9005-79-2